Chuck



Dec. 14, 1954 H. P. SMITH, JR., ET Af. 2,696,987

CHUCK Filed June 24. 1950 Gttorneg United States Patent' iO This iinventen `relates to: asehuek ferstretchiforming and like'machines. Y v

Stretch-forming fmachinesause'ftwo opposedmiraclesv lne-- tween==which extends:sancelongadfmernber, iandarazben'd of-fdesired form"l isl'rnad :saidfmerirber .bytmovingsone or 1 both chucksfrela die' over-whichrthernember isebent, f the chuckslvbeingc s nrovedthatr the :member-.isis also stretched xi-uringzben ng. 'xThe-A:elongated-members that 1are"- stretch-formed1varyifzeonsiderablyf.in 'theirlerosssectionalform. Accordingly;theawinsertsemployedin the Schluck to; -grip i the fendset f the:fniember.'v 'are :required to be custom built according to the specic cross-sectional shape fofthe'fme'mb'er. l:Sinceftheriinserts:must grip with sucientfpower to :prevent .accidental :releaser `t-the @same areat present-'rmade' off V'steel,.'heat-tre'ated1andrhar'dhronre plated, and, lbecausethey are'm'ade especial-ly'rforreach specific job, are'expensive and..dii"1cultftof make.

:Ambjectfot the present `invention:istofprovidefacchuek of i `the character :indicated 1in iwhi'ch-l'the jawfinser'tsuare made lr to' fa "standard formfia commensurately lowerrco'st than 1 special f forms fand to11t.1:said inserts with"-hardenedv gripping elements having operating V`faces thatlcoriform to the pcross-sectionl of theirrrerlribergripped thereby. .Th the Jy gripping f elementsfonly: need i be f especiallyfon madeya-nd, the.kv samei beirrgrelatively ismallerethan'tlfie'tinserts, rare hardened-1iandffplated -with f-.easie'r facilityli'than were 'the prior '.inserts. A

"The invention als'orhas's-forits" Objects! tot provide-much means f'rthat `are positive :in operation,convenienteinfuse,- eas'ily :installed 1ina worlsingflpositionf andaeas'ilyudisco'nnected therefrom, economical.- off-manufacture,lrelatvely simple, "andl of general superiority and; service'ability..

ilhefinvention also' comprisesrnovel details-01:11construe-I tion andf novel; combinations fand-arrangementsoi'zparts, whichiwlill :more fullyappear inAV fthezcour'se: ofiithe'ffellowing description. Howeverthe drawings merlelyfshow and the following description merely describes embodiments of the preseent iinv'efrtio'n; Whichf arelgivenfbyiwayfof illustration or example only. i

In the drawingsQlike reference haracters`designate sirnilar partsjn the several views.

iTiig.l 1i iswamend.viewofta-.chuck iittedwith workg'ripping insertsf.accordngttonthe Hp-resentflirrvention; thellatter being shown. asformedctomgrip.acpieceft work-'having a Tse'ction.

FigfLZl. is, a; sideelevational.viewaltheref in quarterV section.

fFig..3 is=a1crossvsectionalview as .takenfon linelf EigiZ.

.FigsJ4 tof`7, inclusive,...arercrossfsectional views-showingftheI inserts .tot Figs. 1to v3..prcivided with Workgi'ippingk elements .designedilo grip tvarious iotherfeirtns44 .f Work pieces. v

lFig., 8 isiaffsimilar. view showinga `lrriodiiication 42in which the inserts are diierently proportioned.

Fig. 9 is a longitudinal section of one of the inserts drawn to an enlarged scale.

The chuck that is illustrated comprises a generally crcular body that is composed of a cylinder 10 at the rear, a tapered housing 11 at the front, a ring 12 connecting the cylinder and housing, and a transverse plate 13 between the adjacent ends of said cylinder and housing. The chuck is mounted on a bar 14 and is moved to retracted or projected position thereby.

The cylinder 10 is provided with a cylinder bore 15 in which is tted a piston 16 having an extension 17 extending through a central bore in plate 13. The latter has a 2,696,987 i Rtented tDec. 14, 195.4

ice y headwforme'ctrbyfan annulartgroove :139.4 .IA radial bore 20is`forntte' inl-"the:fcylinderjthelsamelbeingfsuppiiedwith airlorrdthertuidurider pressurethrough fiarpa'ssage; L21.

of 'f the vUvvork--piecesflto'flare gripped ccsnsiderably.A `-iHowevergfth`e g-rea pieeesifhave' retailv er@ss'ser;tional-:l ensionsf that1'de'iine a-'fcertainfrnaximumnarea. iTheiset insertsf-ZZac'cordhigh/,isf provided'ew -a-tseat29 ofsuch sizeJt-hatithe set offiielements 8i ttedltherein:will-:handle Woikqieces f suehfrmaxfirnumf'seetional area.

'The setf insertstamaylvaryin 'number'. "in 'thist case, 30,131" and32,-'comp'r` 'ethe'se't. "-Together, 'outerconical "ia'ce`133 f that engages' face fZS Each linsertfat the rearfthereo tl wthias'e'atG42nvwhieh head-'218i-iswengagedyan e evidenti-themen ttrdinalfnievemeatffseidffhed will tfeetz projectioneoiifretraction;as the: casel 'may be; of said set fofinse'rts.

"Assumirrgiasetfef insertsL thathas lar-sm-ll'iiiarneter f six iiiiehesg1 ithe seat 1&2-9fprcvid'e'd "therein preferably have 1an "area 'ofls'om enfftol'twelvesor thirteen-square e orners135'1'ffseatl29'fare suitablyy :spacedvfrom Mace/133 Iso las E4not zito-7y unduly Aweaken any of the inserts. Accordingly, seat 29maybeftwofa-1id onelltalff by :four ifi-riches., :las suggested #1in '-"Figs 'y 3 fto "-7, three; and :onehaflffby'thredihehesaasa show n'inFig. -8, or three Iandronhailf inchesvsquare. "1"hus`,=atmost,1 two-or three A` sets-1df'finserts, having seats as exemplified-above, will serveuto-faccommodate practically' llfforms of" workpieces-within" therra-ngefofvsize f the chuck.

L'lhefstandardf-setfon sets finsertsffthus yprovided' canE be easilyttediwith a=set 'of w irkgrippingelements/28l 'that are sof requiredha"rdness,` land 'since f said'telem'ents Vare relatively; lsrlnaillerffthan lthe inserts, Vthey-are' xmore lreadily produced for asp'eeial-job.

`Tlhezigripping!:elementsetwtllmre shownashintegral parts. As shown in Figs. 7 and 8, they may be fabricated of two or more pieces 42 of rectangular cross-section for further facility of production.

It will be noted that 'the inserts 30, 31 and 32, in addition to the conical surface thereof, are each defined by longitudinal'faces that are substantially at right angles to each other, the same defining lines of cleavage between the inserts that are outside of and parallel to the faces of seat 29 and to the axis of the housing 11. Said lines or planes of cleavage are spaced in practice, to insure gripping by the hardened blocks and/ or. strips.

Means, such as screws 43, may serve to secure the specially formed sets of elements 28 to the set of inserts 27 andl to reduce the' shear of such screws, the forward ends of said insertsare preferably provided with abutments 44 for elements 28, as clearly shown in Figs. 1 and 9.

Frornthe foregoing, it will be seen that a standard or basic set of inserts that are easily produced in quantity, can readily be fitted with specially formed gripping elements at lower cost than if a set of inserts were specially formed for each particular job of work. i

In the usual manner, bolts 45 are employed to retain the inserts in circumferential spaced relationship in all positions thereof and, when projected to grip a work-piece, to maintain the various surfaces of the seat 29 in parallel relationship one with the other, one such bolt being provided for each insert and extending through guide slots 26 into threaded seats 46 provided in said inserts.

While the invention that has been illustrated and described is now regarded as the preferred embodiments, the constructions are, of course, subject to modications Without departing from the spirit and scope of the invention. It is therefore not desired to restrict the invention to the particular forms of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a chuck for use in a stretch-forming or like machine, a work-piece gripping structure comprising, in combination: a housing having a conically tapered inner face converging toward an open end of said housing; a plurality of jaw inserts disposed in said housing, said inserts having outer conical faces complementary to and adapted for cooperation with said inner face whereby said inserts will be moved radially inwardly upon movement thereof axially outwardly from said housing, said inserts being circumferentially spaced one from the other to define lines of cleavage that are substantially at right angles to each other; a seat formed in an adjacent pair of said inserts, said seat having walls disposed in parallel relationship to the axis of said housing and to the surfaces of said lines of cleavage; a plurality of hardened gripping elements disposed and engaging the walls of said seat and adapted for cooperation with at least one of said surfaces of said lines of cleavage on another of said inserts, said elements being especially shaped to conform to and to grip a workpiece of angular cross-sectional conguration; and means for retaining said gripping elements in position with respect to said seat.

2. ln a chuck for use in a stretch-forming or like machine, a work-piece gripping structure comprising, in combination: a housing having a conically tapered inner face converging toward an open end of said housing; a plurality of jaw inserts disposed in said housing, said inserts having outer conical faces complementary to and adapted for cooperation with said inner face whereby said inserts will be moved radially inwardly upon movement thereof axially outwardly from said housing, said inserts being circumferentially spaced one from the other to dene lines of cleavage that are substantially at right angles to each other; a seat formed in an adjacent pair of said inserts, said seat having walls disposed in parallel relationship to the axis of said housing and to the surfaces of said lines of cleavage; a plurality of hardened gripping elements disposed in and engaging the walls of said seat and adapted for cooperation with at least one of said surfaces of said lines of cleavage on another of said elements, said elements being especially shaped to conform to and grip a work-piece of angular cross-sectional configuration; screw means for retaining said gripping elements in contact with said seat; and abutments formed on the outer ends of said inserts and extending into the space defined by at least one of said lines of cleavage for engaging the outer ends of said gripping elements thereby to take axial 4 thrust of said elements under pull of said work-piece in said chuck.

3. In a chuck for use in a stretch-forming or like machine, a work-piece gripping structure comprising, in combination: a substantially cylindrical housing having a conically tapered inner face converging toward an open end of said housing; three jaw inserts disposed in said housing, said inserts having outer conical faces complementary to and adapted for cooperation with said inner face whereby said inserts will move radially inwardly upon movement thereof axially outwardly from said housing, said inserts being circumferentially spaced one from the other to dene lines of cleavage that are at right angles to each other; a rectangular seat formed in two adjacent inserts, said seat having walls disposed in parallel relationship to the axis of said housing and to the surfaces of said lines of cleavage; at least two hardened gripping elements disposed in and engaging the walls of said seat and adapted for cooperation with at least one of said surfaces of said lines of cleavage on the other of said inserts, said elements being especially shaped to conform to and grip a work-piece of angular cross-sectional configuration; screws extending through each of said gripping elements and into adjacent inserts for retaining said gripping elements in contact with said seat; and abutments formed on the outer ends of said inserts and extending into the space defined by at least one of said lines of cleavage for engaging the outer ends of said gripping elements thereby to take axial thrust of said elements under pull of said work-piece in said chuck.

4. In a chuck for a stretch-forming or like machine, a housing having a conically tapered inner face converging toward an open end of said housing, a set of jaw inserts in the housing and having an outer conical face operatively engaged with said inner face whereby said inserts will be moved radially inwardly upon movement thereof axially outwardly from said housing, said set of inserts comprising at least two members which together define a longitudinal seat having spaced side portions extending parallel to the axis of said housing and having a standard size and shape whereby said set of inserts is adapted to be produced in quantity, a set of hardened gripping elements in said seat and secured to the inserts, said elements having cooperating faces extending axially parallel to said housing and especially formed to engage and grip a work-piece of irregular cross-sectional form, the seat in the set of inserts being of such relative size to the area of the smaller end of said set of inserts that a minimum distance is provided between said conical face of the set of inserts and that portion of the seat which most nearly approaches said conical face, and an abutment on the outer end of said set of inserts for engaging the ends of the hardened gripping elements to take the axial thrust of said elements under pull of a work-piece in the chuck.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 440,255 Austin Nov. 11, 1890 460,601 Skinner Oct. 6, 1891 926,761 Oliver July 6, 1909 1,037,796 Procunier Sept. 3, 1912 1,118,072 Thompson Nov. 24, 1914 1,129,491 Housel Feb. 23, 1915 1,245,361 Lutz Nov. 6, 1917 1,295,994 Lavoie Mar. 4, 1919 1,335,714 Lea Mar. 30, 1920 1,403,415 Iggberg Jan. 10, 1922 1,540,832 Forster June 9, 1925 1,665,250 Atkins Apr. 10, 1928 1,857,012 Corley May 3, 1932 

